二叉树插入、遍历

#include <stdio.h>

/*定义结构体*/
struct tree_param{
    int tree_data;
    struct tree_param *tree_left;
    struct tree_param *tree_right;
};

typedef struct tree_param node;

/*插入函数*/

void tree_insert(node **tree, int value)
{
    node *temp = NULL;
    /*节点*/
    if(!(*tree)){
        temp = (node *)malloc(sizeof(struct tree_param));
        temp->tree_data = value;
        temp->tree_left = NULL;
        temp->tree_right = NULL;
        *tree = temp;
        return;
    }
    /*左小右大*/
    if(value < (*tree)->tree_data){
        tree_insert(&(*tree)->tree_left, value);
    }else if(value > (*tree)->tree_data){
        tree_insert(&(*tree)->tree_right, value);
    }
}

/*清除树*/
void tree_delete(node *tree)
{
    if(tree){
        tree_delete(tree->tree_left);
        tree_delete(tree->tree_right);
        free(tree);
    }
}

/*前序遍历树节点数据*/
void preorder_print(node *tree)
{
    if(tree){

        printf("%d\n", tree->tree_data);
        preorder_print(tree->tree_left);
        preorder_print(tree->tree_right);
    }
}
/*中序遍历*/
void midorder_print(node *tree)
{
    if(tree){

        midorder_print(tree->tree_left);
        printf("%d\n",tree->tree_data);
        midorder_print(tree->tree_right);
    }
}
/*后序*/
void backorder_print(node *tree)
{
    if(tree){
        backorder_print(tree->tree_right);
        printf("%d\n",tree->tree_data);
        backorder_print(tree->tree_left);
    }
}
/*测试*/
int main (int argc, char **argv)
{
    node *root = NULL;

    tree_insert(&root, 9);
    tree_insert(&root, 4);
    tree_insert(&root, 8);
    tree_insert(&root, 5);
    tree_insert(&root, 12);
    tree_insert(&root, 15);
    tree_insert(&root, 20);

    printf("pre printf\n");
    preorder_print(root);

    printf("mid printf\n");
    midorder_print(root);

    printf("back printf\n");
    backorder_print(root);

    printf("begin delete\n");
    tree_delete(root);

    printf("delete OK\n");



    return  (0);
}